TEXTREL binaries are loaded without immutable on un-writeable sections.

After text relocations are finished, these regions (in the binary) can become
immutable.
OPENBSD_MUTABLE section always overlaps writeable LOADs, so don't be afraid
of that case, it's covered.

diff --git a/libexec/ld.so/loader.c b/libexec/ld.so/loader.c
index c23ea6d..1a34127 100644 (file)
--- a/libexec/ld.so/loader.c
+++ b/libexec/ld.so/loader.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: loader.c,v 1.199 2022/11/06 11:43:19 deraadt Exp $ */
+/*     $OpenBSD: loader.c,v 1.200 2022/11/06 12:00:20 deraadt Exp $ */
 
 /*
  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
@@ -757,6 +757,18 @@ _dl_rtld(elf_object_t *object)
                }
        }
 
+       /* 
+        * TEXTREL binaries are loaded without immutable on un-writeable sections.
+        * After text relocations are finished, these regions can become
+        * immutable.  OPENBSD_MUTABLE section always overlaps writeable LOADs,
+        * so don't be afraid.
+        */
+       if (object->dyn.textrel) {
+               for (llist = object->load_list; llist != NULL; llist = llist->next)
+                       if ((llist->prot & PROT_WRITE) == 0)
+                               _dl_mimmutable(llist->start, llist->size);
+       }
+
        if (fails == 0)
                object->status |= STAT_RELOC_DONE;